The parameters charset and attachment_content_type have no effect with the JITL-Job JobSchedulerManagedMailJob

Current Situation

When setting the parameter charset in the job JobSchedulerManagedMailJob, this has no effect for the emails to be sended. The charset iso-8859-1 is used.
When setting the parameter attachment_content_type in the job JobSchedulerManagedMailJob, this has no effect for the emails to be sended. The content-type text/plain is used.

Desired Behavior

It should be possible to set the charset or attachment_content_type for the emails sent by the job JobSchedulerManagedMailJob. The default for the charset should be UTF-8.

Patch

A patch is available here